1. Field of the Invention
The present invention relates to a semiconductor package, and particularly to a semiconductor package in which a semiconductor element is hermetically sealed.
2. Description of the Related Art
Semiconductor packages with semiconductor elements, such as high-frequency semiconductor elements, have been used for various high-frequency devices (for example, refer to JP-A 2001-35948 (KOKAI)). Such semiconductor packages include one (a hermetic seal package) in which a semiconductor element is hermetically sealed, and which includes a base substrate to which the semiconductor element is disposed; a frame body which is provided on the base substrate, and which surrounds the semiconductor element; a lid body which is provided on the frame body; and a connector substrate which is passed through the frame body, and which is provided on the base substrate.
For example, as shown in FIG. 1, a connector substrate 101 is provided on a base substrate 102. The connector substrate 101 is formed of dielectrics, and is a substrate which closes an opening 104 formed in a frame 103 which is a frame body. The connector substrate 101 includes a convex part 105 for closing the opening 104, and a high-frequency signal line 106, which is passed through the convex part 105, is provided to a surface of the connector substrate 101. On the peripheral surface of the connector substrate 101, an outer frame 101a to which W paste is applied, followed by sintering, is provided. The outer frame 101a and the frame 103 are brazed with Ag, and a hermetic seal package is formed.
A portion, through which the high-frequency signal line 106 penetrates, functions as a triconductor part (a stripline part) 106a, and other portion functions as a micro-strip line part. The triconductor part 106a of the high-frequency signal line 106 is formed thinner than the micro-strip line part in order to match impedance of the triconductor part 106a with that of the micro-strip line part (refer to FIG. 1).
However, recently, semiconductor packages have been developed into those with high power. When the width of the high-frequency signal line 106 is made smaller, the insertion loss of a high-frequency signal is increased, and allowable current of the high-frequency signal line 106 is lowered. Consequently, there are cases where the triconductor part 106a of the high-frequency signal line 106 melts.